1. Field of the Invention
The present invention relates, in general, to springs for motors and, more particularly, to a spring used with a motor in an effort to reduce vibration and noise of the motor during operation, and to an optical disk drive having a motor with such a spring.
2. Description of the Prior Art
As well known to those skilled in the art, optical disk drives are devices for recording on and/or reproducing information data from disks using optical systems. Such an optical disk drive comprises a turntable provided on a deck base for seating a disk thereon, a drive means for rotating the turntable, an optical pickup device for recording on and/or reproducing data from the disk while rectilinearly reciprocating over the surface of the disk in a radial direction of the disk, and a pickup-moving means for rectilinearly reciprocating the pickup device.
FIG. 1 is a plan view, showing the construction of a conventional optical disk drive.
As shown in the drawing, the conventional optical disk drive comprises a turntable 20 provided on a deck base 10 at a predetermined position for seating an optical disk thereon. This turntable 20 is connected to the rotating shaft 22a of a first drive motor 22 installed in the deck base 10, and is rotated by the rotating force of the motor 22.
A longitudinal opening 12 is horizontally formed in the deck base 10 along the central axis of said base 10 such that the opening 12 is leveled with the turntable 20. An optical pickup device 40 is installed on the deck base 10 such that the pickup device 40 is movable along the longitudinal opening 12.
In a detailed description, a lead screw 14 is installed on the deck base 10 at a predetermined position such that the screw 14 extends in parallel to the opening 12. The lead screw 14 is selectively rotated in opposite directions by a drive means 30. A longitudinal guider 16 is placed on the deck base 10 at a position opposite to the lead screw 14 while extending in parallel to the lead screw 14.
The pickup device 40 has a pickup base 42, which is provided with an objective lens 44 for concentrating light beams in a specified direction to focus the beams on a desired point on the surface of the disk. Two internally threaded pieces 46 are formed along a first edge of the pickup base 42 at positions opposite to the guider 16. The two internally threaded pieces 46 engage with the lead screw 14 such that they are linearly moved along the lead screw 14 in response to a rotating motion of the screw 14. A guide piece 48 is formed at a second edge of the pickup base 42, and movably engages with the guider 16, so the guide piece 48 is linearly moved along the guider 16 when the two internally threaded pieces 46 are linearly moved along the lead screw 14. Therefore, the pickup device 40 rectilinearly reciprocates in a radial direction of the disk in accordance with the opposite directional rotation of the lead screw 14.
The drive means 30 for rotating the lead screw 14 comprises a second drive motor 32 which is a reversible motor installed at a predetermined position on the deck base 10. A drive gear 34 is mounted to the rotating shaft of the motor 32 such that the gear 34 is rotated along with the rotating shaft in the same direction. The drive means 30 also has a driven gear 38 fixedly and concentrically mounted to an end of the lead screw 14. The driven gear 38 is rotated in conjunction with the drive gear 34 due to a middle gear 36 engaging with both the drive and driven gears 34 and 38. That is, the rotating force of the drive gear 34 is transmitted to the driven gear 38, with the middle gear 36 acting as a power transmission gear.
When the second motor 32 is rotated in a direction during operation of the optical disk drive, the lead screw 14 is rotated in the same direction, and the pickup device 40 is linearly moved in accordance with the rotating motion of the lead screw 14. The second motor 32 can be rotated in opposite directions, so the pickup device 40 can linearly reciprocate along the lead screw 14, thus recording on or reproducing data from the disk.
However, the conventional optical disk drives typically use sled motors or feed motors as their second drive motors for the lead screws, so the optical disk drives are problematic in that the motors may undesirably generate vibration and noise during operation, and negatively affect the operational performance of the optical disk drives.
In the prior art, the manufacturers of optical disk drives, who cannot themselves find any specific measure to counter such vibration and noise of motors installed in their products, only produce optical disk drives using spec motors purchased from motor manufacturers who produce the motors without carefully considering that their motors may be used in optical disk drives which require silent motors with reduced vibration and noise.
Therefore, when the spec motors installed in the optical disk drives unexpectedly generate severe vibration exceeding a predetermined maximum level, the motors cause the gears and other devices which are cooperating with the motors to be excessively vibrated and generate noise, thus ill-affecting the operational performance of the optical disk drives, in addition to disturbing those around the disc drives.